It is my pleasure to follow the invitation by AV magazine to contribute an article. The support by animal welfare organizations from Europe and increasingly from the U.S. has always been instrumental to our work both directly collaborating with us and indirectly by raising public awareness and political support. No mentally sane person enjoys carrying out experiments which entail the suffering of animals. By putting forward the 3R principles (reduce, refine, replace) a compromise formula was found between the societal need to advance research and to limit animal use, which is nowadays widely accepted by scientific and animal welfare organizations. This 3R concept requires a continuous development of science towards less animal use and suffering. Animal welfare organizations play a central role in maintaining the drive of this process. I will attempt a comparative analysis of the validation of alternative methods in Europe and the U.S., unavoidably simplifying and giving my personal perception addressing here a more general audience.